Subsets of very low risk Wilms Tumors show distinctive gene expression, histologic, and clinical features
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE14767 | GEO | 2009/12/22
SECONDARY ACCESSION(S): PRJNA112147
REPOSITORIES: GEO
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Project description:The goal of this study is to define biologically distinct subsets of Very Low Risk Wilms Tumors (VLRWT) using oligonucleotide arrays. Description: 52 tumors from the original case:cohort of 600 tumors from NWTS-5 met the criteria for VLRWT. Thirteen tumors were excluded for quality control reasons, resulting in 39 tumors for analysis. Global gene expression analysis was performed on these 39 tumors. A total of 4,000 probesets representing the greatest variability according to coefficient of variation was utilized for hierarchical clustering, and three clusters were identified. Two subsets within VLRWT are identified that have pathogenetic and molecular differences and apparent differences in risk for relapse. If these predictors can be prospectively validated, this would enable future clinical stratification and broadening the definition of VLRWT. Experiment Overall Design: Global gene expression analysis was performed on 39 tumors that met the criteria of VLRWT and passed quality control parameters in order to define biologically distinct subsets. Experiment Overall Design: Hierarchical clustering identified three tumor clusters (C1, C2 and C3). The top differentially expressed genes were identified by first filtering out probesets with a maximum expression of less than 6.5 in all 39 tumors. Using the remaining 14,452 probesets, the expression of each cluster was compared with the expression in the remaining tumors, and those genes with a p-value <0.00001 and positive or negative fold-change (FC) of greater than 2.5 were identified. This resulted in 161 probesets from the comparison of C1 with C2+C3, 43 probesets from the comparison of C2 with C1+C3, and 71 probesets from the comparison of C3 with C1+C2. The false discovery rates were 0.02%, 0.06% and 0.05% for C1, C2, and C3, respectively. These three lists were combined, resulting in 239 probesets (161 genes) which are provided in Supplemental Table 1, linked below.
2010-01-19 | E-GEOD-14767 | biostudies-arrayexpress
Project description:PURPOSE:Recent studies suggest that children <24 months with stage I favorable histology Wilms tumors <550 g [very low risk Wilms tumors (VLRWT)] have an excellent prognosis when treated with nephrectomy only, without adjuvant chemotherapy. The identification of risk categories within VLRWT may enable refinement of their definition and optimization of their therapy. EXPERIMENTAL DESIGN:To define biologically distinct subsets, global gene expression analysis was done on 39 VLRWT that passed all quality-control parameters and the clusters identified were validated in an independent set of 11 VLRWT. Validation of select differentially expressed genes was done with immunohistochemistry on a tissue microarray from 20 of 39 tumors. Loss of heterozygosity (LOH) for 11p15, 1p, and 16q was analyzed in 52 tumors using PCR. RESULTS:Two distinctive clusters were identified. One cluster included 9 tumors with epithelial differentiated tubular histology, paucity of nephrogenic rests, lack of LOH for 1p, 16q, and 11p, absence of relapse, and a unique gene expression profile consistent with arrest following mesenchymal-to-epithelial transition. The second cluster included 13 tumors with mixed histology, intralobar nephrogenic rests, and decreased expression of WT1. Three of 6 relapses occurred in this cluster. Of 43 informative tumors, 11p LOH was present in 5 of 5 relapses and 11 of 38 nonrelapses. CONCLUSIONS:Two subsets comprising a total of 56% of VLRWT are identified that have pathogenetic and molecular differences and apparent differences in risk for relapse. If these predictors can be prospectively validated, this would enable the refinement of clinical stratification and less arbitrary definition of VLRWT.
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Project description:Chronic lymphocytic leukemia (CLL) stereotyped subsets #6 and #8 include cases expressing unmutated B cell receptor immunoglobulin (BcR IG) (U-CLL). Yet, subset #6 (IGHV1-69/IGKV3-20) is less aggressive compared to subset #8 (IGHV4-39/IGKV1(D)-39) which has the highest risk for Richter’s transformation among all CLL. The underlying reasons for this divergent clinical behavior are not fully elucidated. To gain insight into this issue, here we focused on their gene expression profiling and performed RNA-seq.
2019-04-04 | E-MTAB-6962 | biostudies-arrayexpress
Project description:Chronic lymphocytic leukemia (CLL) stereotyped subsets #6 and #8 include cases expressing unmutated B cell receptor immunoglobulin (BcR IG) (U-CLL). Yet, subset #6 (IGHV1-69/IGKV3-20) is less aggressive compared to subset #8 (IGHV4-39/IGKV1(D)-39) which has the highest risk for Richter’s transformation among all CLL. The underlying reasons for this divergent clinical behavior are not fully elucidated. To gain insight into this issue, here we focused on epigenomic signatures and their links with gene expression, particularly investigating genome-wide DNA methylation profiles in subsets #6 and #8 as well as other U-CLL cases not expressing stereotyped BcR IG using the Illumina 450k methylation arrays. Additionally we analysed the methylation profiles of naive and memory B cell subsets from healthy donors and compared them with those of the CLL cases.
2019-04-04 | E-MTAB-6955 | biostudies-arrayexpress
Project description:Whether stromal components facilitate growth, invasion, and dissemination of cancer cells or suppress neoplastic lesions from further malignant progression is a continuing conundrum in tumor biology. Conceptualizing a dynamic picture of tumorigenesis is complicated by inter-individual heterogeneity. In the post genomic era, unraveling such complexity remains a challenge for the cancer biologist. Towards establishing a functional association between cellular crosstalk and differential cancer aggressiveness, we identified a signature of malignant breast epithelial response to stromal signaling. Proximity to fibroblasts resulted in gene transcript alterations of >2-fold for 107 probes, collectively designated as Fibroblast Triggered Gene Expression in Tumor (FTExT). The hazard ratio predicted by the FTExT classifier for distant relapse in patients with intermediate and high grade breast tumors was significant compared to routine clinical variables (dataset 1, n = 258, HR--2.11, 95% CI 1.17-3.80, p-value 0.01; dataset 2, n = 171, HR--3.07, 95% CI 1.21-7.83, p-value 0.01). Biofunctions represented by FTExT included inflammatory signaling, free radical scavenging, cell death, and cell proliferation. Unlike genes of the 'proliferation cluster', which are overexpressed in aggressive primary tumors, FTExT genes were uniquely repressed in such cases. As proof of concept for our correlative findings, which link stromal-epithelial crosstalk and tumor behavior, we show a distinctive differential in stromal impact on prognosis-defining functional endpoints of cell cycle progression, and resistance to therapy-induced growth arrest and apoptosis in low vs. high grade cancer cells. Our experimental data thus reveal aspects of 'paracrine cooperativity' that are exclusively contingent upon the histopathologically defined grade of interacting tumor epithelium, and demonstrate that epithelial responsiveness to the tumor microenvironment is a deterministic factor underlying clinical outcome. In this light, early attenuation of epithelial-stromal crosstalk could improve the management of cases prone to be clinically challenging.
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Project description:Cancer associated fibroblasts (CAFs) are highly heterogeneous and different subsets of CAFs may exhibit distinct functions, To identify the molecular signature of distinctive CAFs , we compared mRNA expression profiles of CAFs isolated from tumors in sensitive patients and resistant ones before neo-adjuvant chemotherapy. Compared the CAFs from sensitive samples, those from refractory samples exhibited a distinctive signature.
2018-01-08 | GSE108565 | GEO
Project description:Polyoma virus nephropathy (PVAN) is a common cause of kidney allograft dysfunction and loss. Microscopic descriptions of PVAN are very similar to T-cell mediated rejection (TCMR) and have unclear underlying molecular mechanisms. To identify PVAN-specific gene expression, we analyzed 162 kidney biopsies with and without PVAN for global gene expression. Unsupervised hierarchical clustering analysis of all 162 biopsies revealed high similarity between PVAN and TCMR gene expression. Increasing the stringency for the specificity (p <0.001 and >2-fold expression) between PVAN and TCMR, 158 and 252 unique PVAN and TCMR injury-specific probesets were observed, respectively. While TCMR-specific probeset were overwhelmingly involved in immune response costimulation (CTLA4, CD28, CD86) and TCR (NFATC2, LCP2) signaling, PVAN-specific probesets were mainly related to viral replication process (IFITM1, LTF, NOSIP, RARRES3), RNA polymerase assembly (POLR2l, TAF10, RPS15) and pathogen recognition receptors (C1QA, C3, CFD). A principal component analysis using these genes further confirmed the most optimal separation between the 3 different clinical phenotypes. Validation of 4 PVAN-specific probesets (RPS15, CFD, LTF, and NOSIP) by QPCR and further confirmation by IHC of 2 PVAN-specific proteins with anti-viral function (LTF and IFITM1) was done, showing significantly higher expression within interstitial cellular infiltrates and in tubuli in PVAN specimens as compared to TCMR and NL kidney biopsies. In conclusion, even though PVAN and TCMR kidney allografts share great similarities on gene perturbation, particular PVAN-specific transcripts were identified with well-known anti-viral properties that provide tools for discerning PVAN and AR as well as attractive targets for rational drug design.
2016-09-30 | GSE72925 | GEO
Project description:Background: Histologic grade in breast cancer provides clinically important prognostic information. However, 30%-60% of tumors are classified as histologic grade 2. This grade is associated with an intermediate risk of recurrence and is thus not informative for clinical decision making. We examined whether histologic grade was associated with gene expression profi les of breast cancers and whether such profi les could be used to improve histologic grading. Methods: We analyzed microarray data from 189 invasive breast carcinomas and from three published gene expression datasets from breast carcinomas. We identified differentially expressed genes in a training set of 64 estrogen receptor (ER)-positive tumor samples by comparing expression profiles between histologic grade 3 tumors and histologic grade 1 tumors and used the expression of these genes to define the gene expression grade index. Data from 597 independent tumors were used to evaluate the association between relapse-free survival and the gene expression grade index in a Kaplan-Meier analysis. All statistical tests were two-sided. Results: We identified 97 genes in our training set that were associated with histologic grade; most of these genes were involved in cell cycle regulation and proliferation. In validation datasets, the gene expression grade index was strongly associated with histologic grade 1 and 3 status; however, among histologic grade 2 tumors, the index spanned the values for histologic grade 1-3 tumors. Among patients with histologic grade 2 tumors, a high gene expression grade index was associated with a higher risk of recurrence than a low gene expression grade index (hazard ratio = 3.61, 95% confidence interval = 2.25 to 5.78; P<.001, log-rank test). Conclusions: Gene expression grade index appeared to reclassify patients with histologic grade 2 tumors into two groups with high versus low risks of recurrence. This approach may improve the accuracy of tumor grading and thus its prognostic value. NB: The patients coming from Uppsala Hospital have been also used in other studies as in GSE3494. You can find the common set of patients in removing the abbreviation "UPP_" from the sample names and compare the results with the "INDEX (ID)" from the GSE3494 series. Keywords: disease state analysis
2006-02-16 | GSE2990 | GEO
Project description:Colorectal adenocarcinoma (CRA) is characterized by marked heterogeneity and may be composed of an admixture of various histologic patterns, including well-formed gland and cribriform types. Although tumors displaying a prominent or predominant cribriform feature are frequently found in CRA, this type may contain specific histologic variants with a characteristic molecular alteration. We investigated the molecular features of 51 primary CRAs with a predominant cribriform histology using array-based analyses [somatic copy number alterations (SCNAs); mRNA expression]. Mutations (TP53, KRAS, PIK3CA and BRAF) and DNA methylation status were also analyzed. The crypt isolation method was used to obtain isolated tumor glands of each type separately. All patients were classified by their CRA histologic subtype into two groups: well-formed gland and cribriform. Next, we performed cluster analysis to stratify SCNA and mRNA expression patterns between the two subtypes. Two distinctive subgroups were stratified based on patterns of SCNA and mRNA expression and were correlated with each histologic subtype. The cribriform type was characterized by a high frequency of SCNA compared with that of the well-formed gland type and was closely associated with the expression of specific mRNAs. In addition, the frequency of KRAS mutation was significantly higher in the cribriform type than in the well-formed gland type. Finally, there was no difference in DNA methylation status between the two subtypes. Overall, these data suggest that the cribriform type provides important insights into colorectal carcinogenesis, suggesting specific potential histologic implications based on the molecular profile.
| S-EPMC9234757 | biostudies-literature
Project description:Background: Histologic grade in breast cancer provides clinically important prognostic information. However, 30%-60% of tumors are classified as histologic grade 2. This grade is associated with an intermediate risk of recurrence and is thus not informative for clinical decision making. We examined whether histologic grade was associated with gene expression profi les of breast cancers and whether such profi les could be used to improve histologic grading. Methods: We analyzed microarray data from 189 invasive breast carcinomas and from three published gene expression datasets from breast carcinomas. We identified differentially expressed genes in a training set of 64 estrogen receptor (ER)-positive tumor samples by comparing expression profiles between histologic grade 3 tumors and histologic grade 1 tumors and used the expression of these genes to define the gene expression grade index. Data from 597 independent tumors were used to evaluate the association between relapse-free survival and the gene expression grade index in a Kaplan-Meier analysis. All statistical tests were two-sided. Results: We identified 97 genes in our training set that were associated with histologic grade; most of these genes were involved in cell cycle regulation and proliferation. In validation datasets, the gene expression grade index was strongly associated with histologic grade 1 and 3 status; however, among histologic grade 2 tumors, the index spanned the values for histologic grade 1-3 tumors. Among patients with histologic grade 2 tumors, a high gene expression grade index was associated with a higher risk of recurrence than a low gene expression grade index (hazard ratio = 3.61, 95% confidence interval = 2.25 to 5.78; P<.001, log-rank test). Conclusions: Gene expression grade index appeared to reclassify patients with histologic grade 2 tumors into two groups with high versus low risks of recurrence. This approach may improve the accuracy of tumor grading and thus its prognostic value. NB: The patients coming from Uppsala Hospital have been also used in other studies as in GSE3494. You can find the common set of patients in removing the abbreviation "UPP_" from the sample names and compare the results with the "INDEX (ID)" from the GSE3494 series. Experiment Overall Design: 64 microarray experiments from primary breast tumors used as training set to identify genes differentially expressed in grade 1 and 3. Experiment Overall Design: 129 microarray experiments from primary breast tumors of untreated patients used as validation set to validate the list of genes and its correlation with survival. Experiment Overall Design: No replicate, no reference sample. **NOTE** There are some inconsistencies between the sample annotation provided by GEO for this experiment in the GSE2990_family.soft.gz file and the supplementary data file GSE2990_suppl_info.txt. ***
2008-06-13 | E-GEOD-2990 | biostudies-arrayexpress